The present invention relates to a medical safety device and, more particularly, to a tracheostomy safety device and its use.
Tracheostomy devices are extensively used within the medical field to ventilate or assist patients with respiratory problems. Many patients with advanced stages of gas exchange impairment (e.g. COPD, multiple sclerosis, emphysema, etc.) are dependent upon effective utilization of the tracheostomy devices to supply oxygen and discharge exhaled gases from the respiratory system. Any inadvertent or unwanted cessation of the respiratory exchange by the tracheostomy devices within the medical unit can lead to irreparable injury or death of the patient.
The ventilator units are usually equipped with sensory or alarm systems designed to detect certain abnormalities such as gas pressure loses within the device. Typically a sudden operational decrease in back pressure activates a remote alarm system so as to alert the medical staffing so that the device may be restored to a life sustaining operation.
One of the most popular tracheostomy devices is a device referred to as a Shiley disposal cannula low pressure cuffed tracheostomy device manufactured and distributed by Mallinokrodt, Inc. (St. Louis, Mo. 63134) fitted with a rigid neck plate and what is referred to as a STRONGHOLD retainer for harnessing the tracheostomy device so that the inner cannula cannot be inadvertently separated from the outer cannula.
The SHLEY device includes an inner cannula and an outer cannula operatively connected to an oxygen or air supply and a low pressure sensory for the alarm system. The outer cannula includes a larger tubular section with an inflatable cuff encompassing a distal end section of the tube and a notched flanged rim at a proximate tube end with a flared seating collar for connecting to the inner cannula. The inner cannula comprises a tubular passageway fitted with a projecting tubular portion and a collared seat for seating and sealing onto the flanged collar of the outer cannula. The projecting tubular portion of the inner cannula is sized to concentrically fit within the outer cannula passageway. The inner cannula functions as an air passageway for ventilating the patient. An enlarged hollow cylindrical extension capped with a brim which anchors the stem of the projecting tubular portion completes the air pathway of the inner cannula. The enlarged tubular air line cylindrical extension having a larger external diameter than the outer diameter of the outer cannula serves as a connecting site for a ventilator connecting elbow which connects the ventilator gas supply lines to the tracheostomy device.
The cylindrical extension also serves as a mounting site for mounting the outer cannula onto the inner cannula. The brim of the cylindrical extension includes a pair of aligning ledges which mate onto notched sections of the notched rim. The extension has the appearance of a hollow cylindrical member with the tubular section spouting outwardly from the stem of the opposite end. The cylindrical member serves as a connecting site for a connecting elbow for the air supply lines.
The cylindrical extension includes a flared seat on the latching side which sealingly fits against flared collar of the outer cannula. A pair of jutting ledges extending outwardly from the top edge of brim of the cylindrical extension of the inner cannula serves as a support for the latching assembly. The cylindrical member is equipped with a pair of latching assemblies which latched the outer cannula to the inner cannula. The latching assemblies outwardly extending ledges are laterally positioned at a sufficient outwardly position so as to provide annular clearance for the latches from the outer cannula rim. The undersides of the extending bridges are notched with channeled grooves to impart improved hingeability to the latches.
The latching assemblies of the inner cannula include a pair of flexible latches in the form of extending arms along the outer peripheral margin of the jutting ledges which extend upwardly and inwardly terminated by L-shaped latching tab or claw which engage onto the notched rim of the outer cannula so as to snuggly hold the outer cannula rim onto the inner cannula rim. The arms extend downwardly and outwardly from the ledges to form depressing tabs which, when depressed, place the latches in an unlatched position.
When used, the outer cannula is inserted into the trachea of the patient with the inflatable cuff inflated to seal the outer cannula to the trachea. The inner cannula tube with the connected or unconnected gas supply lines is then inserted onto the outer cannula in a seating position and then latched together with the latches. Normally the harness for the neck plate is secured to the patient to hold the tracheostomy unit in place when ventilation of the patient is commenced. A ventilating elbow connector forms a connecting elbow between the inner cannula and the air lines to the air sources. When the STRONGHOLD anti-disconnect device is used, it straps the elbow connector to the neck plate so as to prevent the elbow connector and the inner cannula from being inadvertently separated from the outer cannula.
Unfortunately, the aforementioned tracheostomy device creates problems for an impaired patient which, if uncorrected, can cause irreparable damage or death to the patient. The ventilating device, with or without the STRONGHOLD, creates serious health risks to patients using the Shiley ventilating device. Without the STRONGHOLD, the latches for latching the inner cannula to outer cannula can become unlatched causing a disruption of the crucial air supply to the patient. Obese patients with excessive neck fat or double chins can unknowingly manipulate the latches with the neck excess sufficiently to unlatch the latching system. This causes a break in the air passageway and a severance of air supply to the patient. Since the inner cannula remains connected to the air source, the sensing system will not detect any appreciable decrease in gas back pressure and, therefore, will not sound the alarm system. Consequently, the medical staffing will be unaware that the patient is in distress and will die if the problem remains uncorrected.
Another particularly serious problem arises in the case of those tracheostomy devices equipped with the STRONGHOLD when the unattended patient becomes restless, startled or panicked by respiratory or ventilating irregularities. Panicky or startled patients will often grasp the connecting elbow of the tracheostomy device with such force so as to pull the entire device, including the inflated cuff, from the trachea causing the ventilating gases to escape into the atmosphere. Since the inner cannula remains connected, there is no detectable back pressure decrease so that the alarm system will not normally detect and sound the alarm under these life-threatening conditions. When an ambulatory patient coughs to clear a plug in the throat, the startled patient will often unconsciously grasp or elbow the device so as to dislodge the entire device, including inflated cuff, from the trachea often causing serious harm or injury to the patient. Thus, the addition of the STRONGHOLD anti-disconnect device does not alleviate those problems associated with the tracheostomy device.
There exists a need to avoid unwanted disconnection of the inner cannula from the outer cannula. There exists a need for an anti-disconnect device which prevents unlatching but yet permits a detectable separation at the connecting elbow. There exists a need for an anti-disconnect device which prevents unwanted unlatching of the inner cannula from the outer cannula and unwanted disengagement of the entire tracheostomy device including the inflated cuff from the patient""s trachea. If the latching system could be maintained latched until knowingly unlatched by hospital or medical staffing, patients needlessly suffering of loss of life or serious injury could be avoided. Crucial notice of a failure of a patient""s tracheostomy unit by timely sounding of the alarm system would avoid catastrophic injury or death to the user of the device.
Safety of using a tracheostomy device by preventing unauthorized or undetected separation of the inner cannula from the outer cannula can be achieved by installing a latching stop against the latches so as to prevent unwanted unlatching. An annular retaining ring buttressed against the latches effectively prevents an unlatching movement of the latches and maintains the latches in the latching position. The latch retaining ring is positioned so as to prevent a patient from intentionally or unintentionally removing the latching stop from the unlatching position. This allows only the authorized personnel to remove the latching stop from the latching position. The latch retaining ring prevents only separation or unlatching of the inner cannula from the outer cannula. If separation of ventilating passageway occurs, it occurs at the connecting elbow, thus, preserving the inflated trachea cuff and the alarm system.
The latching stop mechanism allows the low pressure alarming system to perform its intended function of alarming medical personnel in crucial life-threatening situations. Failure of the alarming system to notify medical staffing of an undetectable separation of the inner cannula from the outer cannula is effectively avoided by the inclusion of the latching stop mechanism of this invention.